Automatic wear adjusting mechanism



June 8, 1954 R. w. HALBERG 2,680,505

AUTOMATIC WEAR ADJUSTING MECHANISM Filed Feb. 19. 1948 IN V EN T 0R. Eager-2 h fiazle 'a Patented June 8, 1954 UNITED STATES PATENT OFFICE 2,680,505 AUTOMATIC WEAR ADJUSTING MECHANISM Robert W. Halberg, Chicago, 111., assignor to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Application February 19, 1948, Serial No. 9,491 2 Claims. (01. 192-111) 2 This invention relates to an automatic adjust- The automatic adjusting mechanism constituting mechanism particularly dapted for use as a in this invention is particularly useful in con- Weal' D mechanism for frictionally engage nection with friction clutches or friction brakes able clutch and brake devices. similar to the clutch shown in the applicants co- It is an object of this invention to provide a pending application Serial No. 8,099, filed Februsimple, fool-proof, accurate, automatic adjusting ary 13, 1948, and now Patent Number 2,562,613, mechanism to compensate for the wear of the but is not restricted to such mechanisms as it is frictionally engageable surfaces of a clutch, brake, possible of adaptation to any form of mechanism or similar device. wherein an automatic adjusting device is desired. It is a further object of this invention to pro- In the drawings the adjusting mechanism has vide an automatic wear-take-up mechanism for been shown associated with a friction clutch asa device having a plurality of relatively movable sembly wherein i represents a flywheel to which members wherein the members are actuated by a cover plate 2 is suitably connected. Floatingly some form of pivotally 0r oscillatably mounted supported within the cover plate 2 is a pressure lever means. The wear take-up mechanism hereplate 3 adapted to be moved into and out of ening disclosed is automatically operated by the ingagement with the friction facings i of the clutch crease in the amplitude of movement of the acdisc 5. Pivotally mounted on the cover plate 2 tuator means due to the wear of the frictionally is a pressure plate actuator lever 1 adapted to be engageable surfaces. rocked about its pivot pin 8 by means of a recip- It is a further object of this invention to prorocatably mounted roller 9 which rides along the vide an adjusting mechanism that W111 automatitI'ElCKVt ay it of the actuator 7 Due to the slopes cially compensate for the normal Wear of the assoof the trackway i ii and the position of the actuciated parts of the device on which it is installed ator pivot pin 8, an over-center mechanism is and thus maintain predetermined clearances beprovided for rocking the actuator lever 1 about tween the associated parts throughout the life 5 its pivot point when the roller 9 rides along the of the device. trackway Hi. Threadably mounted in actuator It is a further object of this invention to prolever l is a stud 12 having its forward end bearing vide an automatic wear take-up means that is against the pr s ur pl d i2 is adapted operated by the actuating mechanism of the to be turned up against pressure plate 3 to vary structure on which the take-up device is installed. the clearances between the flywheel i, the pres- By reason of this feature the number of parts of sure plate 5, and the friction facings 4.

the take-up device is reduced to a minimum and By means of threaded stud I2 the normal cleara positive form of automatic adjusting means is anccs between t e r on gs, the flywheel provided. and the pressure plate may be varied and auto- Additional objects and advantages of this inmatically controlled. The rearwardly protruding vention will become apparent from the specificaend of stud 52 contains a bore i4 adapted to reion and attached drawings wherein; ceive a ratchet or free-wheeling mechanism l5.

Fig. 1 is a sectional side elevational view of one i mechanism 15 is adapted to Cause the rotaform of my adjusting mechanism sh w a tion of the stud [2 in a clockwise direction such ciated with the related parts of a plate-type fricthat the forward end of stud 12 will be moved toi tional clutch assembly; wards the pressure plate 3. This ratchet or free- Fig. 2 is a rear elevational view of the mech wheeling mechanism comprises a one-way gripnism shown in Fig. 1; ping member i 5 carried in the bifurcated forward Fig. 3 is a sectional view taken along the line d Ha f the r dkey operator Gr pss of Fig. 2 illustrating the shape and arrange 4 s member It is a substantially ed bent m-ent of the ratchet mechanism gripping spring strip which is diametrically disposed in the her; bore Hi of stud ii. The side leg i 6a of gripping i is a sectional side elevational View of a member 95 is adapted to pivot about the base leg modified form of adjusting mechanism shown IE2) when torque is applied to the side leg through sociated with th r lated parts of p1ate type so the key operator l7. Clockwise rotation of the friction clutch assembly; side leg Eta causes the free end edges of legs Ifia Fig. 5 is a rear elevational view of the adjusting and It?) to bite into the wall of the bore It and a mechanism shown in Fig. 4; and torque transmitting connection results. When Fig. 6 is a sectional elevational view taken along side leg I 6a is turned counterclockwise it is swung thellne 65 of Fig. 4. 55 about the base leg 16b and this disengages the n free end edges of the legs Ilia and 16b from the wall of the bore m and the member 16 rotates in the bore it. Because the free end edges of member l6 bite into the walls of the bore Hi when member i is turned clockwise the stud I2 is rotated in a clockwise direction. When gripping member I6 is rotated in a counterclockwise direction it slips inthe bore 24 of stud l2 and there is relative motion between the gripping member and stud H! with no rotation of stud 2.

The means for applying torque to the gripping member if: includes the key operator 11 which has a rearwardly extending portion ill) protruding from the stud bore i l. This-portion llb is provided with turning wings 18. One of the wings i8 is adapted to be positioned between the leg portions of the U-shaped bracket member at which is mounted on the cover plate 2. Bracket member carries an adjusting screw 23, the threaded end of which is adapted to be located adjacent the wing is that is positioned within bracket 2i.

As the roller 9 reciprocates along the trackway 56, of the clutch lever actuator J, the actuator l is rocked about its pivot pin 8 and the stud means i2 is moved into and out of engagement with the pressure plate 3. When stud means 12 is forced against pressure plate 3 the friction facings 4 are frictionally engaged with the flywheel i and the pressure plate 3. After repeated engagement of the friction facings 4 with pressure plate 3 and flywheel I the friction facings 4 become worn and consequently it requires increased pivotal movement of actuator l to cause engagement of these members.

The ratchet mechanism l5 and the particular arrangement of its associated control elements provides means for converting the increased amplitude of pivotal movement of the actuator lever i into an operating means for the automatic adjusting mechanism herein disclosed. By positioning a key operator wing i8 between the bracket leg 21a and the threaded end of adjusting screw 23, there is provided a means for rotating the key operator H in a clockwise direction as the wear of the friction facings t increases the amplitude of pivotal movement of the actuator 1. Rotation of operator 6'! results from the successive engagement of wing 18 with screw 23 and bracket leg 21a as roller 9. reciprocates along trackway l0 during operation of lever actuator 1. On the rearward movement of roller ii the actuator is rocked forwardly and if clutch facings 4 are worn this engages wing it with the threaded end of adjusting screw 23 and consequently ro' tates the key operator 1'! in a counterclockwise direction. Due to the ratchet connection between the key operator l'i and the stud l2 this counterclockwise rotation of the key operator I! does not turn the stud l2 but the counterclockwise rotation of the wing it reduces the amplitude of uninterrupted swing of wing 18 on the return swing of the actuator 1. Subsequently, as roller 3 moves forwardly along trackway Hi, to rock actuator E rearwardly, the wing I8 is forced against the leg 21a of the bracket 2! and this rotates the key member ii in a clockwise direction. Clockwise rotation of the key operator ll turns the stud l2 in a clockwise direction and threads the stud forwardly through its threaded mounting in actuator 1 thereby moving the pressure plate 3 closer to the friction facings 4 of the clutch disc 5.

As long as there is no appreciable wear of the friction facings d the actator E has substantially thrust member constant amplitude of swing about its pivot pin 8 and the wing l8 of key operator I1 is not pressed into engagement with either the adjusting screw 23 or the leg Zia of the bracket 2|. Whenever wear of the friction facings 4 causes any appreciable increase in the amplitude of pivotal movement of the actuator 1, engagement of the key operator wing is with the adjusting screw 23 and bracket leg Zia occurs and this automatically threads wardly to compensate for the reduced thickness of the frictionfacings 4. Consequently, the clearances between the friction facings, the pressure plate and the flywheel face are maintained substantially constant.

It is obvious that a pitch for the threads of the stud means l2 can be selected so as to produce any desired forward movement of the stud means 12 for any predetermined increase in the amplitude of swing of the actuator lever T.

The modified form of adjusting mechanism disclosed in Figs. 4 through 6 is shown applied to the same friction clutch construction illustrated in Figs. 1 through 3 and all elements common to both forms carry the same reference numerals. This modified form of adjusting mechanism differs from that shown in Figs. 1 through 3, by having a wedge-operated, slidably mounted, thrust member 32 adapted to actuate the pressure plate 3 instead of the threadably mounted actuating stud member l2 shown in Figs. 1 to 3. In this modified form the pivoted actuator lever i has a longitudinally extending passageway M in which is slidably mounted the link or bolt-like 32. Thrust link 32 is adapted to be adjustably positioned in the passageway 31 of lever l by means of rearrangeable, spring-pressed, cooperating wedge blocks 33 and 34 mounted in a transversely extending slot la on the lever actuator i and having portions extending into transversely extending slot 32a in the thrust member 32. Positioning wedge block 33 has an inclined forwardly facing surface 35 adapted to bear against and ride along an inclined surface 36 formed on the forward wall portion of the transversely extending slot through the thrust member 32. As positioning wedge 33 is moved outwardly in a direction normal or transverse to the length of the thrust member 32, the thrust member 32 is urged forwardly and the clearances between the flywheel l, the friction facings 4 and the pressure plate 3 are reduced. If positioning wedge 33 is retracted towards the actuator lever trackway i!) then the thrust member 32 can be moved rearwardly to increase the clearances between the flywheel, friction facings and pressure plate. Spring 3'! tends to urge positioning wedge 33 outwardly to hold it firmly against the thrust member 32. Looking wedge block 34 has a forwardly facing surface 39 bearing against and adapted to reciprocate along a mating surface 40 formed on the near side of positioning wedge 33. Locking wedge 34 also has an inclined surface M adapted to engage an inclined surface 42 formed on the rear wall portion of the transversely extending slot 32a through the thrust member 32. A hingedly mounted spring strip 44 urges locking wedge 34 outwardly into engagement with the rear surface 40 of positioning wedge 33 and the inclined surface 42 of thrust member 32. Spring means 44 is hingedly mounted on the actuator lever 1 and has a forwardly extending lever arm 44a connected to the locking wedge 34.

The cover plate 2 carries a set screw 45 which is positioned so as to have an end engageable with the forwardly extending lever arm at of spring strip 44 whenever wear of the pivotal movement of the actuator lever '1'. Due to the location of the set screw 45, with respect to the hinging edge 44b of spring means 44, it is possible to get a magnification in the movement of the locking wedge 34 compared to the actual movement of the spring lever arm 44a adjacent the point of contact of the set screw stop means 45 and the lever arm 44a.

This wedge block form of adjusting mechanism functions as follows: As long as there is no appreciable wear of the friction facings Ii the actuator lever 7 rocks about its pivot pin 8 and the strip lever arm 44a is not engaged with the stop means 45 and there is no relative movement between the positioning and locking wedge members 33 and 34 consequently there is no change in the effective length of the thrust member 32. When friction facings 4 become reduced in width, due to wear or the like, then the amplitude of pivotal movement of the actuator lever 7 will be increased and the spring strip lever arm 4411 will be pressed against the stop means 45 during rearward movement of roller 9 ing wedge 34 will be moved downwardly towards the trackway ll] of actuator lever 7. As locking wedge 34 moves downwardly the wedging loch: between blocks 33 and 34 is broken and this permits rearrangement of the blocks, the spring 31 automatically moving the positioning wedge 33 upwardly or outwardly from trackway it when spring lever arm 44a moves block at downwardly or inwardly towards trackway I 0. When positioning wedge 33 moves upwardly or outwardly away from trackway iii the cooperating surfaces 35 and at, of the positioning wedge and the thrust; member respectively, cause a forward movement of the thrust member 32 and this forward movement increases the effective length of the thrust member 32 and compensates for the wear of the friction facings 4.

By choosing the correct angles for the cooperating wedge surfaces of this automatic adjusting means and by selecting materials with proper 1. An automatic adjusting means for a pair of relatively movable, frictionally engageable, members comprising a pivotally mounted actuships, while permitting said blocks to be rebers and positioned so as to be automatically engaged with and to immediately'cause rearrangement of at least one of said wedge block when there is any increase in the amplitude of pivotal movement of said actuator means to maintain the selected amplitude of movement of the actuator means.

locking block varies the effective length of said thrust means, and stop means associated with one of pivotal movement of said actuator means whereby the effective length of said thrust means is varied to regain the normal amplitude of pivotal movement of said actuator means.

Number UNITED STATES PATENTS References Cited in the file of 

